Pull-type tube-expanding tool



March 10, 1942. E, A. DEWALD PULL-TYPE TUBE-EXPANDING' TooL Filed Oct. 1939` Illlll .wb .bmw

kmmh MSK Patented Mar. 1o, i942 lPULL-rinus TUBE-EXPANDING Toor.

Edward Alexander Dewald, Massillon, Ohio, as-

signor, by mesne assignments, to The Babcock & Wilcox Company, Newark, N. E., a corporation of New Jersey Application October 25, 1939, Serial No. 301,092

8 Claims.

This invention relates to straight-line, pull- 1 type, tube-expandingv tools used particularly for expanding boiler and heat exchanger tubes into tube plates and drums. I

In particular this invention provides a suitable. handoperated actuating mechanism for use in manufacturing this type of apparatus in situations Where working space is cramped and for. repair work in the ileld. I'his tool is adapted effectually to operate a pull expander substantial-l ly of the type disclosed and .claimed in the covpending application of Maxwell, Serial No.

274,749, iiled May 20, 1939, a motor-driven actuating mechanism for which is described and claimed in my co-pending application Serial'No. 298,345, filed October 7, 1939.

In the accompanying drawing, Fig. 1 is a longitudinal section through a tool of my invention in place to be used, and Fig. 2 is a section on the line 2-2 of Fig. l.

In the following speciiication and in the appended claims `vthe words outer and "inner" and related terms will be used Vto connote a direction into or out oi the tube to be expanded when the tool is in proper position to accomplish the expanding operation.

In the drawing the mandrel I having an outer threaded portion I3 and an inner threaded portion 8 at the opposite ends thereof is closely but slidably fitted inside the tube 2. The mandrel I, immediately outward from the inner threaded portion 9 thereof, is enlarged. This enlarged portion is tapered throughout its own length to form the tapered portion i having its greatest diameter at its inner end.

The tubey 2 has the threaded portion I6 at its outer end and the expanding head 4 welded as shown at I9 at its vinner end. This expanding head 4 consists of a tube having four longitudinal slots equally spaced around its circumference extending outward from its inner end, one of which is illustrated at I9, and a split expander ring 3 'formed on that inner end. The 2 is closely but slidably fitted into the end cup 9 and passes through the length of the barrel II to the inner end of which the end cup 9 is removably afxed by the set'screwl. The threads of the threaded portion I9r of the tube 2 are ground off on one side as shown in section in Fig. 2, pro- Such elements as the elements 9 and II may be considered asparts of a barrel structure, one

(Cl. 15a-80.5)

end of which is adapted to bear against the end o! a tube to be expanded, and .where such language is used in the claims, it is intended to cover a combination in which an element other than the cylindrical element II itself, may actually contact the tube to be expanded.

The large nut I5 engages the threaded portion I9 of the tube 2 and operates when tightened to draw the tube 2 back through the barrel H and end cup 9. The ease of rotation of the nut I5 is insured by the ball thrust bearing I1 placed around the tube 2 on the shoulder 2 I of the barrel I I and interposed between the outer end of the barrel II and the inner face of the nut I5.

, The small nut I2 engages theouter threaded portion I 3 of the mandrel I and operates when tightened to draw the mandrel I back through the tube 2. The ease of rotation o! the nut I2 is insured bythe ball thrust bearing I4 between the outer end of the tube 2 and the inner face of the nut I2.

'I'he adjusting sleeve G and locking sleeve 'l engaging the inner threaded portion 8 of the ,of the tube 2. The inner end of the tool is then inserted into the boiler tube it is-desired to expand until the outer end of that tube engages the 'capacity of the device.

end cup 9 in annular recess 20. The distance which the expander ring 3 enters the tube to be" expanded may be controlledv by adjustment of the large nut I5 to any desired depth within the This depth is determined by the thickness of the tube sheet into which the boiler tube is to be expanded, 'it being desirable Vto commence the expansion just at 'i the inner face of the tube sheet as indicated in the drawing. Prior to the initiation of the actual expanding.

operation adjusting sleeve 6 is set and locked by the sleeve I in' such a position that when the tightening of the small nut I2 brings the outer end ofthe sleeve 6 in contact with the inner faceof the expander ring 9 the expanded diameter of the ring 9 (caused by the spreading of the segments. of the expander head-4 as the tapered portion 5 of the mandrel I is drawn then removed from the work.

into the expanding head 4), will be the desired inside diameter of the expanded boiler tube. Aftaarden er insertion the small nut` I2 is tightened until the adjusting sleeve 6 and expanding ring 3 are in contact, thus expanding the boiler tube at the point where the expanding ring 3 is placed.

The large nut I5 is then tightened until the expanding ring 3 has been drawn outward through the portion of tube to be expanded. The device is In the operation of my device it will, be obi served that the contact between the adjusting sleeve 6 and the expander ring 3 is maintained throughout the expanding operation by the clamping action of the small nut I2 bearing threaded portion of said mandrel land bearing against the outer end of said tubular member.

2. In a tube .expanding device, a-tubular mem- I ber, a mandrel'within said tubular member exagainst the outer end of the tube 2 through the ball thrust bearing I4.

In constructing my devicethe barrel II is preferably made of soft steel with its outer surface knurled, the end cup 9, of a hardened tool steel and the tube 2, of seamless steel tubing.

' The expanding head I welded to the tube 2 is preferably made of oil hardenedl steel and the mandrel I, of heat-treated steel of high tensile strength. 'Where practicable the operation of my device is best effected with an air wrench, particularly'in the tightening of the large nut I5, since by use of controlled pressure in the op-f eration of the wrench a substantial uniformity in the expanding of the boiler tubes can 'be obtained. However, good results can alsoA be vob- 'tending beyond said' tubular member at both ends thereof, said mandrel having an enlarged portion at its innerend tapering outwardly and having a stop at the inner end of said tapering portion, said tubular member having aA longitudinally split portion anda split expander ring at its innerend, said expander ring being adapted to be expanded by the tapering p0rtion of said mandrel-when brought into contact with the stop thereon, a barrel structure encasing a portion of said tubular member, said barrel structure having an inner end adapted to bear against 'a tube to be expanded, a threaded portion onthe outerend of said tubular member, a nutengaging said threaded portion of said tubular tained, particularly in very close spaces, by the use of hand-operated ratchet wrenches. My device provides a novel and useful tool for achieving the superior results of the ,larger devicesy disclosed in the co-pending applications previously referred to in expanding inaccessible tubes and also inrepairing installations in the field.

It has been found in practice when using my device that the best results are obtained by turning the tool through an angle of 45 about its axis and repeating the expanding operation exactly as hereinbefore described. This second operation brings the solid portions of the split ring expander in contact with the boiler tube where the split portions had been at the first operation Vand serves to iron out the ridges vleft v by those split portions thus leaving the. inside of the expanded tube perfectly cylindrical. 'A

While I-have described and illustrated what I believe to be the best practical embodiment of my. invention, it is to be understood that cer-- tain variations will suggest themselves to those skilled in the art which are a part oi the substance of my invention. Fora denition, therefore, of what I believe to be'- novel and substantial in my'invention attention is directed to the appended claims. i

I claim:

1. In a tube expanding device, a tubular member, a mandrelY within said tubular member extending beyond said tubular member at both ends thereof, said mandrel having an enlarged,

portion at its inner end tapering outwardly and having a stop at the inner end of said tapering portion and said tubular member having a longitudinally spitl portion and a spilt expander ring at its inner end, said expander ring being adapted to be-expanded by the tapering portion of said mandrel when brought into contact with 10' the stop thereon, a barrel structure encasing a portion of said tubular member, said barrel strucfture having an inner end adapted to bear against a tube to be expanded, a threaded portion on member, an anti-friction thrust bearing interposed relative to said nut andthe outer end of saidbarrel structure, a threaded -portion on the outerend of said mandrel, a nut engaging said threadedV portion of said mandrel, and Aan antifriction thrust bearing interposed relative to said nut and theouter end of said tubular member. e 3. In a tube expanding device, a tubular member, a mandrel within said tubular member extending beyond said tubular-memberat both 'ends thereof, said mandrel `having ani enlarged tact with the adjustable stop thereon, a barrel structure encasing a portion of s aid tubular member, said barrel structure' having an annular recess on. its inner end concentric-with said mandrel adapted to bear against and to center said mandrel in the tube to'be expanded and to-center said mandrel therein, a threaded portion on the outer end of said tubular member, a nut engaging said threaded -portion of said tubular member, ,ani anti-friction 'thrust bearing interposed relative' to saidnut and the outer- -end of said barrel structure, a-threaded portion lon the 'outer end of said mandreL-'a nut engaging said threaded portion of said mandreland an anti-friction thrust bearing between said nut and the outer vend .of said tubular 4. A tube'expanding tool comprising a tubular member having at its inner end a split expander head, means for expanding said head, locking means for maintaining the expansion of said head during movement of said tubular member.

a threaded lportion on the outer end of said' tubular member, a barrel structure encasing said tubular member adapted `at its inner end to bear against a tube to be expanded, and a nut engaging the threaded portion of said tubular member and bearing against the outer end of v l said barrel structure and an anti-friction bearin g between said nut and the outer end of said barrel structure. v

5. A tube expanding tool comprising a tubular member having at its inner end a split expander the opter end of said tubular member. a nut Il head. means for expanding 'laid head. locking engaging said threaded portion of said tubular means for maintaining the expansion of said head during movement of said tubular member, a threaded portion on the outer end of said tubular member, said threaded portion having a fiattened face, a barrel structure encasing said tubular member adapted at its inner end to bear against a tube to be expanded, said barrel structure having a key aiiixed therein the inner face of which bears on the flattened face of the threaded portion of said tubular member, and a nut engaging the threaded portion of said tubular member and bearing against the outer end f said barrel structure.

6. A tube expanding tool comprising a tubular' member having at its inner end a split expander head, means for expanding said head, looking means for maintaining ,the expansionv of said head during movement'i(` said tubular member. a threaded portion on the outer end of said tubular member. a barrel structuraencasing said tubular member adapted at its inner end to bear against a tube to be expanded, key means intermediate said tubular member and said barrel structure preventing their relative rotation, and a nut engaging the threaded portion 'of said tubularmember and bearing against the outer end of said barrel structure.

'1. A tube expanding, tool comprising a barrel structure adapted'at its inner end to bear against the tube to be expanded, a tubular member slidably mounted within said barrel structure and having at its inner end a split expander head, means for expanding said head, locking means for maintaining the expansion of said head during movement of said tubular member, a threaded portion 'on the outer end of said tubular member, and a nut engaging the threaded portion of said tubular member and bearing against the outer end of said barrel structure, the turning of said nut operating to cause the withdrawing of the expanded head from the tube.

8. A manually operated mechanicaitube expander for making a pressure tight connection between a tube and a wall formed with tube seat in which an end portion of the tube is tted, a rod-like mandrel adapted to slide freely within said end portion and having an upwardly tapered section near one end, a sectional expander head encircling the mandrel and'slidably mounted thereon, said expander head being adapted to slide freely within said tube in its retracted condition but being expansible by relative movement between it and said tapered section to expand pander head is locked in its expanded condition.

EDWARD DE'WALD.

-Patent: No.2,275,61h.-

4CERTIFICATE oF cronREcTIoN,

, t narh, 1o, 19h2. DwAaD'ALExANDER DEwALD. i

It ishereby certified that error appears in' the printed specification of the above numbered patent requiring correction as follns: Page'2, first column', line''?,l ciaim l, for -"spit portion and a spi1t"\rea'd --splitportion an@ a split-wg' and second colu'mn, line 14,8, claim", strike out "and to center' said mandrel therein";' and that the said Letters Patent should bel read with this 'correction therein that the samefnay conform to. the record of the casein the Patent Office. l Signedand-a-'ealod this 2nd day of vlfehruary, A. D'. 191:5.

. v f -YAHOnJ'y Van. lirsdale,l (S6313 vActing Commissioner of Ie.tents. 4 

